Matcha extract effectively inhibited the growth and adherence of Porphyromonas gingivalis through multiple mechanisms, according to a study published in Spectrum.

The study's in vitro experiments revealed that Matcha extract (ME) significantly suppressed the growth of P. gingivalis, Prevotella nigrescens, and Fusobacterium nucleatum, while showing no inhibitory effects on beneficial oral streptococci and Aggregatibacter actinomycetemcomitans. ME treatment induced notable morphological and physiological changes in P. gingivalis cells, such as nanoparticle formation and reduced membrane fluidity, without compromising membrane integrity. Additionally, the researchers found ME triggered autoaggregation of P. gingivalis in a major fimbriae (FimA)-dependent manner and inhibited bacterial adherence independent of fimbriae.

The researchers conducted a structure-activity relationship analysis and identified the pyrogallol-type B-ring of catechins in ME as essential for the growth inhibition of P. gingivalis. In a pilot clinical trial, the team evaluated the microbiological and therapeutic effects of matcha mouthwash in patients with periodontitis. The results showed a significant reduction in the number of P. gingivalis in saliva post-intervention compared to baseline levels. Although an improvement in probing pocket depth was observed in the matcha group, the researchers believed the difference was not statistically significant.

"The current study is not the first to show that tea-derived catechins have an antimicrobial effect on P. gingivalis. However, our results suggest prophylactic and therapeutic potential for matcha as a multimodal drug for periodontal diseases,” noted the researchers. These findings motivate further clinical studies to assess the therapeutic applicability matcha for possible elimination of P. gingivalis in the oral cavity."

Supported by grants from Matcha and Health Research, MEXT KAKENHI, and JSPS KAKENHI; no author conflicts were disclosed.